For the next two weeks, The Citizens Advertising Takeover Service has replaced 68 ads in a subway station on London’s Tube system with pictures of cats. This is not a marketing stunt. The people behind CATS (get it?) are volunteers who raised the money to do this on Kickstarter. They want to inspire people to think differently about the world and realise they have the power to change it. James Turner, the man behind this initiative, talks about how this all came together on Medium.